JPH045201Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a holding device for a long workpiece when processing a long workpiece in an automatic lathe machine,
More specifically, the process is carried out by providing a plurality of arc-shaped shaft bearing pieces, which are divided into a plurality of pieces so as to form a substantially hollow cylindrical shape in the assembled state, on the rear end flat part of the hollow cylindrical holding device body so as to be freely adjustable. By forming a holding part for the workpiece and having a structure in which the holding part for the workpiece is fixedly attached by screwing or the like to a guide bearing provided on a non-movable fixed part of the automatic lathe machine body, it is possible to hold a long workpiece. can be held securely with less clearance,
Therefore, it is an object of the present invention to provide a workpiece holding device for an automatic lathe machine that can prevent a decrease in machining accuracy due to the influence of workpiece runout or the like.

Traditionally, when machining long objects using automatic lathes, the materials used were relatively soft, so there were no problems during cutting or due to cutting chips. Machining of steel has been increasing, and when cutting such hard steel, the superhard alloy of the guide bearing 12 fixed by a screw 15 to the immovable fixed part 14 of the automatic lathe main body is removed, as shown in FIG. The part 10 normally has an oil film in between, but when it slides with the rotating workpiece 19, it becomes hot and burns out.
When processing hard steel as described above under the same conditions as soft steel, it is necessary to increase the gap between the superhard alloy part 10 of the guide bearing 12 and the workpiece 19 in order to prevent burnout. As a result, there was a drawback of poor processing accuracy.

Furthermore, traditionally, automatic lathes with moving headstocks have been designed for high-precision cutting, and in order to machine hard steel with high precision, the cutting feed must be reduced by 30 to 50 percent compared to soft steel. It cannot be processed and is used as a cooling lubricant for stainless steel to prevent burnout.
Cutting oil that is more than twice as expensive as normal cutting oil had to be used.

In addition, rotary guide bearings are used to prevent burnout as described above, but rotary guide bearings cannot be processed with high precision due to wear of the steel balls caused by bearing gaps and cutting pressure. It was possible.

Furthermore, since the cutting feed is slow, the cutting waste becomes long in the form of a wire and becomes entangled with the workpiece being cut or the cutting tool, causing trouble and causing great trouble during the machining process.

In addition, as a result of many years of research, the present applicant has found that the cause of burnout of the super-hard alloy part 10 of the guide bearing 13 is due to the deflection of the workpiece 19 that occurs during cutting, as shown by the imaginary line in Figure 1. It was discovered that vibration was the cause.

The present invention was devised as a result of repeated trial and error in order to eliminate the above-mentioned drawbacks, and one embodiment of the invention will be described in detail below with reference to the drawings, as shown in Figs. 2 to 4. (a) A screw 1A is carved into the front inner peripheral wall of the holding device main body 1, which is formed into a hollow cylindrical shape, a polygonal tightening chamfered part 1B is provided on the front outer periphery, and a plurality of shaft bearings are provided on the rear end flat part. Female screw portions 5, 5 for single tightening...
(b) The shaft bearing piece 3 has an arc shape as if a hollow cylindrical shape is cut into a plurality of pieces, and a plurality of shaft bearing piece tightening holes 4 are provided at equal intervals on one end surface, and one hole is provided in the diametrical direction. A lubrication nozzle assembly screw 7 is provided, a hollow cylindrical cemented carbide 10 is soldered and welded to the inner circumference, and the other portions of the cemented carbide 10 are polished and polished.
Shaft bearing pieces 3, 3, which are formed by wrapping finishing and which restrain the workpiece cut into a plurality of equal parts, are slid in the diametrical direction on the rear end flat part of the main body 1. It is freely fitted loosely to form a holding part.

(c) Also, in order to fit the shaft bearing piece 3 freely and slidably, the bearing piece tightening hole 4 is made larger than the outer diameter of the bearing piece holding screw 6, or is formed into an elongated hole shape in the sliding direction. (d) Insert the bearing piece holding screws 6 into the bearing piece tightening holes 4 perpendicularly to the region where the bearing pieces 3 are located, and screw them into the bearing piece tightening female screw parts 5 of the holding device main body 1, respectively. Therefore, it is screwed onto a guide shaft bearing 12 which is glued to a stationary part of the automatic lathe machine body of a movable headstock type.

(e) In addition, a lubrication nozzle 8 or a lubrication tube 9 (like the cutting oil nozzle 18, is installed near the split groove of the bearing piece 3 in the lubrication path 2. In this case, the lubrication nozzle assembly screw 7 and the lubrication nozzle 8 are unnecessary. ) is connected to a forced lubrication system (not shown).

Since the present invention has the above-mentioned structure, when using it, (a) First, in order to fix the holding device main body 1 to the immovable fixed part 14 of the automatic lathe machine main body, which is a fixed object, Fit the guide bearing sleeve 13 into the fixed part 14 of the automatic lathe machine body, tighten it in place with the guide bearing sleeve presser screw 15, and (b) insert the guide bearing 12 into the guide bearing sleeve 13 and adjust it. Screw in the tightening ring nut 11 and tighten the cemented carbide part 10 of the guide bearing 12 to match the diameter of the workpiece. (Up to this point, the mounting method is the same as the conventional mounting method.) (C) Next, screw the holding device main body 1 into the threaded part of the guide bearing 12, and tighten the adjustment tightening ring nut 11.
(iv) Insert the bearing piece holding screw 6 into the bearing piece tightening hole 4 of the bearing piece 3, and screw it into the bearing piece tightening female screw part 5 of the holding device main body 1.

(E) When using the oil nozzle 8, screw the oil nozzle 8 into the oil nozzle assembly screw 7 of the bearing piece 3.

(f) Put the workpiece from the moving spindle 17 to the holding device and the guide bearing 12, and then move the workpiece to the moving spindle 17.
(g) While adjusting the shaft bearing pieces 3 one by one to the diameter of the workpiece, tighten the shaft bearing pieces 3 with the shaft bearing piece holding screw 6.
(H) Also, attach the cutting blade 16 and move the moving spindle 17.
At the same time as the machine rotates, cutting oil is injected into the guide shaft bearing at the front and the holding device at the rear, and a handle (not shown) for automatic cutting feed is pulled to cut the workpiece.

When machining is performed as described above, even if the cutting feed rate of a long workpiece is increased, the shaft bearing piece 3 of the holding device holds the workpiece, so that the workpiece 19 is not deflected as in the conventional example shown in FIG. , cutting runout is eliminated,
Furthermore, by forcibly supplying oil from the oil supply path 2, the superhard alloy portion 10 of the guide bearing 12 will burn out even if a load is applied that reaches the limit of damage to the cutting tool, that is, the cutting feed amount is six times or more than the conventional one. Without a doubt,
As a result, the cutting feed rate can be increased, reducing machining time and eliminating cutting runout.
The lifespan of the cutting tool is more than twice that of the conventional one.

In addition, conventionally, the gap between the cemented carbide part 10 of the guide bearing 12 and the workpiece has been adjusted from 3/100 mm to 1/100 mm in diameter, but with this device installed, the gap between the cemented carbide part 10 of the guide bearing 12 and the workpiece has been adjusted to 3/1000 mm. Even when adjusted in microns, there will be no burnout, so machining accuracy is excellent, and expensive cutting oil is not required. By installing the holding device of the present invention, the number of cutting chips is drastically reduced compared to the conventional one, and troubles caused by cutting, such as small spiral or ring-shaped cutting chips broken in half, are completely eliminated.

As a result of the various experiments described above, we were able to discover unexpected phenomena, and as a result of further research, we were able to complete a device that has greater practical effects and is able to achieve the goals we have longed for.

In addition, in this device, the conventionally used expensive guide bearing 12 can be used as is without changing the shape.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a sectional view showing a fixed guide shaft bearing of a conventional automatic lathe machine, and Fig. 2 is a cross-sectional view showing a fixed guide shaft bearing of an automatic lathe machine. FIG. 3 is an exploded perspective view of each part of the holding device of the present invention attached to the fixed guide shaft bearing, and FIG. 4 is a perspective view of each shaft bearing piece. It is. In the figure, 1 is the holding device main body, 2 is the oil supply path, 3 is the bearing piece, 4 is the bearing piece tightening hole, 5 is the female thread for tightening the bearing piece, 6 is the bearing piece holding screw, 12 is the guide bearing, and 14 is the This figure shows the immovable fixed part of the automatic lathe machine body.

Claims (1)

[Scope of utility model registration request] A workpiece is secured by providing an arc-shaped shaft bearing piece, which is divided into a plurality of parts so as to form a substantially hollow cylindrical shape in the assembled state, on the rear end flat part of the hollow cylindrical holding device body so as to be slidable and adjustable in the diametrical direction. 1. A workpiece holding device for an automatic lathe machine, characterized in that the workpiece holding portion is mounted on a guide bearing provided on an immovable fixed portion of an automatic lathe main body.